---
title: "21.B.520 Investigation — Annex I, Initial Airworthiness · Avioverse"
description: "The competent authority shall perform sufficient investigation activities to justify the issuance, or revocation of the permit to fly."
url: "https://avioverse.aero/regulations/easa/initial-airworthiness/annex-i/section-b-procedures-for-competent-authorities/21-b-520"
---

# 21.B.520 Investigation

Annex I · Regulation (EU) No 748/2012 · EAR revision 27 Nov 2025

IR Implementing rule

## 21.B.520 Investigation

(a) The competent authority shall perform sufficient investigation activities to justify the issuance, or revocation of the permit to fly.

(b) The competent authority shall prepare evaluation procedures covering at least the following elements:

1\. evaluation of the eligibility of the applicant;

2\. evaluation of the eligibility of the application;

3\. evaluation of the documentation received with the application;

4\. inspection of the aircraft and for unmanned aircraft, of the CMU;

5\. approval of the flight conditions in accordance with point 21.A.710(b).

IR · 21.B.520 — Regulation (EU) No 748/2012 · Regulation (EU) 2024/1108 · Initial Airworthiness Easy Access Rules · EAR revision 27 Nov 2025

AMC Acceptable means of compliance

## AMC 21.B.520(b) Application for a permit to fly

The competent authority must receive an application for permit to fly in a form and manner established by that authority, e.g. on EASA Form 21 (see below) completed by the applicant.

| Application for [Part 21](https://avioverse.aero/glossary/easa/part-21) Permit to Fly                                                                                                                                                                                                                                                                                                                                                   |                      |                                                 |
| --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------- | ----------------------------------------------- |
| 1. Applicant:                                                                                                                                                                                                                                                                                                                                                                                                                           | \[Name of applicant] |                                                 |
| 2. Aircraft nationality and identification marks:                                                                                                                                                                                                                                                                                                                                                                                       |                      |                                                 |
| 3. Aircraft owner:                                                                                                                                                                                                                                                                                                                                                                                                                      |                      |                                                 |
| 4. Aircraft manufacturer/type                                                                                                                                                                                                                                                                                                                                                                                                           |                      | 5. Serial number                                |
| 6. Purpose of flight \[Use terminology of 21.A.701(a) and add any additional information for accurate description of the purpose, e.g. place, itinerary, duration…] \[For an application due to a change of purpose (ref. 21.A.713): reference to initial request and description of new purpose]                                                                                                                                       |                      |                                                 |
| 7. Expected target date(s) for the flight(s) and duration                                                                                                                                                                                                                                                                                                                                                                               |                      |                                                 |
| 8. Aircraft configuration as relevant for the permit to fly 8.1 The above aircraft for which a permit to fly is requested is defined in \[add reference to the document(s) identifying the configuration of the aircraft. Same as required in AMC 21.A.263(c)(6) or AMC 21.A.709(b) application approval form 18A or 18B, box 6] 8.2 The aircraft is in the following situation related to its maintenance schedule: \[Describe status] |                      |                                                 |
| 9. Approval of flight conditions \[if not available at the time of application, indicate reference of request for approval] \[Reference to: 1. EASA approval, if flight conditions are approved by EASA; or 2. DOA approval form (see AMC 21.A.263(c)(6)), if approved under DOA privilege; or 3. Competent authority approval.                                                                                                         |                      |                                                 |
| 10. Date:                                                                                                                                                                                                                                                                                                                                                                                                                               |                      | 11. Name and signature: \[Authorised signatory] |

EASA Form 21

AMC · AMC 21.B.520(b) — Regulation (EU) No 748/2012 · ED Decision 2012/020/R · Initial Airworthiness Easy Access Rules · EAR revision 27 Nov 2025

[All rules in SECTION B — PROCEDURES FOR COMPETENT AUTHORITIES](https://avioverse.aero/regulations/easa/initial-airworthiness/annex-i/section-b-procedures-for-competent-authorities)

Consolidated from the EASA Easy Access Rules (revision 27 Nov 2025, extracted 13 Oct 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.